Finding the center of a circle

[Jetsi]

Here is what I am trying to do:

I have a 6 foot wood dowel like the kind you hang your clothes on in your closet, which I use as a practice bo staff. What I am trying to do is to make it so I can have it in three sections which will fit in my luggage. I spend a fair amount of time on the road and have been trying to find a way to practice bojutsu/kendo/saber twirling. The three pieces together would make a great bo (and are marked to show the width of a double Maul hilt :twisted: ), and only using two of the pieces gives me a 46" bokken.

So I stopped in at the local Home Depot today and bought some wood dowel screws, chopped my practice bo into three pieces, and have begun putting it together. Good thing wood is cheap, because I was having a problem getting the hole perfectly centered. The pieces when put together form an "almost" straight line.

So the question is (finally), does anybody have any foolproof way of finding the center of a circle?

And before it gets pointed out, the DHS and the TSA are not in a position to search my luggage, so taking it on an airliner is fine.

[xwingband]

Yum geometry... The foolproof way requires being able to find a midpoint of a line.

You make a chord on the circle. Mark the midpoint on this line and draw a line perpendicular to it through this point. That second line is now a diameter.

I believe the correct geometric proof is to repeat it with a second chord and diameter to get the center, but if you are in a position to accurately measure you can just find the midpoint of the diameter.

[JadedMonk]

Or you can get one of these

http://www.ares-server.com/Ares/Ares.asp?MerchantID=RET01229&Action=Catalog&Type=Product&ID=82285

Or something similar. Shipping from Micromark tends to be obscene. For $13 i don't know if you would ever use it again.

[xwingband]

That works the same way! :D If you look it's only making a 45 degree to perpendicular and using a tangent chord because it's more convenient to do in one pass.

[supertrogdor]

I immagine that drilling a perfectly straight hole would be a bigger problem, maybe consider using 2 or 3 smaller dowels in a linear or trianglular pattern, the slight inconsistancy would also help hold it together.

[kinchar bamin]

drilling holes in dowel must be hard unles u use a vice

[Jetsi]

You know, I was good at geometry. In Junior High :oops: .

However, the little contraption shown did give me an idea. If I put the dowel on the floor and flat against a board, and put my carpenters square with the 45 degree line flat against the board, it should do the same thing.

The easiest way may be to cut a small 1/2 inch piece off, find the center, and then use it as a template on the remaining pieces. That could cause problems, too, as careful inspection of these dowels has shown me that the diameter is inconsistent and they are not a perfect circle.

And the drilling I think will be easier, as the drill has levels on it, and I have a vise to help me out. I will hopefully get it done today, take some pics if successful and put them up.

[Jetsi]

Pictures are a little late, but better than never.

All put together.
http://i165.photobucket.com/albums/u49/jetsi/DSC06825.jpg

Showing the width compared to a double maul set.
http://i165.photobucket.com/albums/u49/jetsi/DSC06827.jpg

With one piece removed, a transportable bokken.
http://i165.photobucket.com/albums/u49/jetsi/DSC06831.jpg

Close up of "hilt"
http://i165.photobucket.com/albums/u49/jetsi/DSC06832.jpg

It works really well, even though I didn't get the screws in 100% straight. But that actually works to my favor. As I screw it together, one side contacts the other first instead of flush, but a little pressure and I can slightly bend the screw and finish putting it together. That resistance adds to some stability, and keeps it from unconnecting while using it.

Overall, I am pretty happy with how it worked out.

[Darth Tollo]

Glad that worked out for you dude. I still don't see why you can't just have it as carry on... :D

[Hasid Lafre]

cause its like 7foot long.

[Jetsi]

And if they don't let hockey sticks or golf clubs on, they aren't going to let this on either.

[GFORCE13]

Jetsi glad it worked out I did the same thing with PVC and it comes apart in the middle so it can become 2 seperate sabers, as soon as I finish up the painting I will post a couple of pictures. 8)